I am building a 408 with either diamond -2cc pistons or wiseco -8cc pistons using the l92 heads and l76 intake. I planned on going n/a but thinking about a 150 wet shot. what would be a good SCR ratio for a street driven a4 3600 stalled 408 with a 150 wet shot. I probably wont be using it all the time so would I be safe with the plasma/moly rings or should I upgrade. Also will the cam have to be custom for nitrous? For fuel I will be using 42lb injectors and a single walbro pump.

Looking for any advice on what sytems to buy and extra stuff i might need.

 

I have the Dura Molly and good to a 300rwhp shot, or more. No, you do not need a dedicated n2o cam at that level, just a nice split with more duration and a little more lift on the exhaust. The exhaust needs help when running n2o, and the unported for n2o l92 heads are not the best flowing on the exhaust side compared to other heads. My 408 I chose a 11.25:1 compression ratio for running 92 octane on the street.
Robert

 

408 on a 150 shot would be pushing it for a single Walbro, you could be looking at close to 700rwhp. May look into doing a double pumper. The 42lb injectors would be fine as long as it's not a dry shot. For that you may need 60's or larger.

Click the link in Robert's signature, I've got a writeup in there.

 

Compression could be pretty much any where depending on how radical you want the cam to be. Most people stick between 11.0-12.0:1.

 

Read through some of the right up bookmarked it for later. How would running a dual in tank set-up vs a 255 in tank and a inline effect street driving or which would be better.

 

I will give my view on this as well. The dual in tank is an easy way to do the F-bodies. They can support 1000rwhp. You can set them up like the in-line and have the option of running the 2nd pump only when you want to (just some special wiring at the pumps). For me, having an additional full add on fuel system was my choice for ease of use and for setting it up on a WS, and the fact that there are so many more pumps to meet any need. I just don't like having the extra pump running and heating up the fuel (most gets returned to tank, over and over) unnecessarily. Either way is great, just depends on what you want. Some even just tap into the existing fuel supply line with an extra in-line pump, though not my first choice. IMO, getting the return and regulator at the rails is paramount for either style, even stock.
Robert